Method of casting en-bloc cylinders



Nov. 14, 1933. c. SKBROWN METHOD OF CASTING EN-BLOC CYLINDERS QJMWW ATTORN EYS changes to which, the different sections of the Patented Nov. 14, 1933;

I 1,935,109} 7 g r METHODHOFCASTING EN-BLOC CYLINDERS I '7 g V 1 Charles S. Brown, Syracuse, N. Y;

g ApplicationNovember 23, 1931 I I Serial No. 576,664

3'Olaims. (ores-156.4)

This invention relates to air cooled internal combustionengines, and has for its object, a multi-cylinder block for air cooled engines, and the method ;of forming the .same.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawing in which like characters designate corresponding parts in all the views.

Figure 1 is a plan view of the finished cylinder block.

Figure 2 is a fragmentary side elevation thereof before the cylinders are separated. I

Figure 3 is an inverted plan view of the block.

Figure l is an enlarged, fragmentary, side elevation of the finished block.

Figure 5 is a sectional view on line 5-5, Figure 4.

The cylinders of multi-cylinder air cooled engines have heretofore, for the most part, been formed separately, or individually, and assezne bled separately on the crank case of the engine. It has been thought necessary to form them separately in order to center them and maintain center alinement and distance between surfaces of the cylinders, because in air cooled engines, spaces for the cooling air must be provided around the cylinders, and there can be no masses of metal joining the hotter portions of the cylinders, as in water cooled engines, since the masses of metal expand and contract unevenly under the uneven heat of the engine, and distort the cylinders tied together, out of alinement.

One of the objects of this invention is an air.

cooled, multi-cylinder en-bloc engine by which the cylinders can be machined accurately, and yet, the cylinders react individually or independently of each other to the different temperature cylinders are subjected, and without one cylinder being affected by the expansion, elongation, or contraction of any other cylinder.

The block here illustrated is for'the type of engines in which the cylinder heads are detachable.

The method of forming the air cooled cylinder block includes casting a plurality of cylinders enblock with integral or connecting pieces, one at the head and one at the base between adjacent cylinders, machining the cylinders and then partly separating the cylinders by cutting the connecting pieces at the head end, leaving the cylinders integrally joined together at their base ends'onlY-r resp e ifica yathe method consists in casting a plurality of cylinders with a base slab common to all of them, with a head slab or tie-piececommon to all of them, with heat radiating flanges encircling the upper portions'of the cylinder and terminating short of the base slab,

the slabs holding'the cylinders as a unit during machining operations, machining the bores and head surfaces of the cylinders and then, cutting through the head slab between the cylinders, thus separating the cylinders so that they can, under working conditions, act independently of each other and react independently of each other to variations in temperature.

The method further consists in casting a rigid connection between adjacent cylinders below the heat radiating flanges and joining the base slabs withthe connection extending along the median plane of the cylinder, that is, a plane containing the axes of the cylinders.

The block produced by this process thus con- &

sists of a base slab, a plurality of cylinders mounted on the base slab and integral therewith, with heat radiating flanges and rigid connection below the radiating flanges and connected to the base along the median line of the cylinders.

designates the base slab common 'to all of the cylinders, which slabis provided with suitable bolt or screw holes for attaching the base to the crank case of an engine.

11 designates the head slab, 12 the cylinders Iv Liv having horizontal heat radiating flanges 13 below the head slab and terminating above the base slab 10.

14 designates the rigid connection extending between the adjacentcylinders along the median line of the cylinders, the connection 14 terminating short of the lowermost heat radiating flanges. The connection is here shown as T shaped in cross section, although it is not 'necessarily so shaped. The head 15 of the T, as here shown, reinforces the connection to tie the base portions of the cylinders together and to the base slab to hold the base portions as firmly as possible from movement during the operation of the engine. .After the bores of the cylinders are machined, and the outer face of the head slab ll'machined for receiving the heads of the cylinders, the head slab 11 is cut at 16 along lines extending between the cylinders, so as to entirely'separate the head ends of the cylinders,

whereby they can act individually under running conditions.v Preferably, the head slabs 11 are formed with transverse grooves 17 in their upper faces along which grooves the cuts are made between the cylinders. These grooves are merely for the purpose of facilitating the machining of the head face of the slab 11.

The head slab is provided with suitable holes 18 for receiving the screws, studs or bolts which hold the heads on the cylinders. Thus, during the machining operations, the cylinders are a unit and held rigidly for machining, and owing to the separating of the cylinders at their head ends after the machining operations,"the cylinders are free to act independently of each other, as they must in air cooled engines under the varying temperature conditions to which various parts of the cylinders are subjected in-the normal operation of the engine.

What I claim is:

1. The method of casting enbloc cylinders for air cooled internal combustion engines consisting in casting a plurality of cylinders with a common base slab, and a common head slab connecting them, and heat radiating flanges on the cylinders between the slabs, machining the cylinders and thereafter cutting the head slab between the cylinders to separate the cylinders at that end.

2. The method of casting en-bloc cylinders for air cooled internal combustion engines consisting in casting a plurality of cylinders en-bloc with a common base piece connecting them and with integral connecting pieces between them above the base piece, machining the cylinders and thereafter cutting the connecting pieces to partly separate the cylinders, leaving them connected by the base piece only.

3. The method of casting en-bloc cylinders 

